Bicycle fork

A bicycle fork is the part of a bicycle that holds the front wheel.

A fork typically consists of two blades which are joined at the top by a fork crown. Above the crown, a steerer tube attaches the fork to the bicycle and the handlebars (via a stem) allowing the user to steer the bicycle. The steerer tube of the fork interfaces with the frame via bearings called a headset mounted in the head tube.

At the bottom of the fork, dropouts hold the wheel. Usually, either the axle is bolted to the fork, or a skewer passes through a hollow axle, clamping the axle to the fork.

The term fork is sometimes also used to describe the part of a bicycle that holds the rear wheel, which on 19th Century ordinary or penny-farthing bicycles was also a bladed fork. On most modern bicycle designs the rear wheel is now attached to a rear triangle made up of multiple triangulated tubes, rather than an actual fork, but the rear fork usage persists.

Dimensions

Forks have several key dimensions which include: offset, length, width, steerer tube length, and steerer tube diameter.